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<a name="gst-plugins-base-libs-Descriptions"></a><div class="titlepage"></div>
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<td valign="top">
<h2><span class="refentrytitle"><a name="gst-plugins-base-libs-Descriptions.top_of_page"></a>Descriptions</span></h2>
<p>Descriptions — Provides human-readable descriptions for caps/codecs
and encoder, decoder, URI source and URI sink elements</p>
</td>
<td class="gallery_image" valign="top" align="right"></td>
</tr></table></div>
<div class="refsect1">
<a name="gst-plugins-base-libs-Descriptions.functions"></a><h2>Functions</h2>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="functions_return">
<col class="functions_name">
</colgroup>
<tbody>
<tr>
<td class="function_type">
<a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gchar"><span class="returnvalue">gchar</span></a> *
</td>
<td class="function_name">
<a class="link" href="gst-plugins-base-libs-Descriptions.html#gst-pb-utils-get-source-description" title="gst_pb_utils_get_source_description ()">gst_pb_utils_get_source_description</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gchar"><span class="returnvalue">gchar</span></a> *
</td>
<td class="function_name">
<a class="link" href="gst-plugins-base-libs-Descriptions.html#gst-pb-utils-get-sink-description" title="gst_pb_utils_get_sink_description ()">gst_pb_utils_get_sink_description</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gchar"><span class="returnvalue">gchar</span></a> *
</td>
<td class="function_name">
<a class="link" href="gst-plugins-base-libs-Descriptions.html#gst-pb-utils-get-decoder-description" title="gst_pb_utils_get_decoder_description ()">gst_pb_utils_get_decoder_description</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gchar"><span class="returnvalue">gchar</span></a> *
</td>
<td class="function_name">
<a class="link" href="gst-plugins-base-libs-Descriptions.html#gst-pb-utils-get-encoder-description" title="gst_pb_utils_get_encoder_description ()">gst_pb_utils_get_encoder_description</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gchar"><span class="returnvalue">gchar</span></a> *
</td>
<td class="function_name">
<a class="link" href="gst-plugins-base-libs-Descriptions.html#gst-pb-utils-get-element-description" title="gst_pb_utils_get_element_description ()">gst_pb_utils_get_element_description</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a>
</td>
<td class="function_name">
<a class="link" href="gst-plugins-base-libs-Descriptions.html#gst-pb-utils-add-codec-description-to-tag-list" title="gst_pb_utils_add_codec_description_to_tag_list ()">gst_pb_utils_add_codec_description_to_tag_list</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gchar"><span class="returnvalue">gchar</span></a> *
</td>
<td class="function_name">
<a class="link" href="gst-plugins-base-libs-Descriptions.html#gst-pb-utils-get-codec-description" title="gst_pb_utils_get_codec_description ()">gst_pb_utils_get_codec_description</a> <span class="c_punctuation">()</span>
</td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect1">
<a name="gst-plugins-base-libs-Descriptions.includes"></a><h2>Includes</h2>
<pre class="synopsis">#include &lt;gst/pbutils/pbutils.h&gt;
</pre>
</div>
<div class="refsect1">
<a name="gst-plugins-base-libs-Descriptions.description"></a><h2>Description</h2>
<p>The above functions provide human-readable strings for media formats
and decoder/demuxer/depayloader/encoder/muxer/payloader elements for use
in error dialogs or other messages shown to users.</p>
<p>gst_pb_utils_add_codec_description_to_tag_list() is a utility function
for demuxer and decoder elements to add audio/video codec tags from a
given (fixed) <a href="/usr/share/gtk-doc/html/gstreamer-1.0/GstCaps.html#GstCaps-struct"><span class="type">GstCaps</span></a>.</p>
</div>
<div class="refsect1">
<a name="gst-plugins-base-libs-Descriptions.functions_details"></a><h2>Functions</h2>
<div class="refsect2">
<a name="gst-pb-utils-get-source-description"></a><h3>gst_pb_utils_get_source_description ()</h3>
<pre class="programlisting"><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gchar"><span class="returnvalue">gchar</span></a> *
gst_pb_utils_get_source_description (<em class="parameter"><code>const <a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gchar"><span class="type">gchar</span></a> *protocol</code></em>);</pre>
<p>Returns a localised string describing a source element handling the protocol
specified in <em class="parameter"><code>protocol</code></em>
, for use in error dialogs or other messages to be
seen by the user. Should never return NULL unless <em class="parameter"><code>protocol</code></em>
 is invalid.</p>
<p>This function is mainly for internal use, applications would typically
use <a class="link" href="gst-plugins-base-libs-Missing-plugins.html#gst-missing-plugin-message-get-description" title="gst_missing_plugin_message_get_description ()"><code class="function">gst_missing_plugin_message_get_description()</code></a> to get a description of
a missing feature from a missing-plugin message.</p>
<div class="refsect3">
<a name="gst-pb-utils-get-source-description.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody><tr>
<td class="parameter_name"><p>protocol</p></td>
<td class="parameter_description"><p>the protocol the source element needs to handle, e.g. "http"</p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
<div class="refsect3">
<a name="gst-pb-utils-get-source-description.returns"></a><h4>Returns</h4>
<p> a newly-allocated description string, or NULL on error. Free
string with <a href="/usr/share/gtk-doc/html/glib/glib-Memory-Allocation.html#g-free"><code class="function">g_free()</code></a> when not needed any longer.</p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="gst-pb-utils-get-sink-description"></a><h3>gst_pb_utils_get_sink_description ()</h3>
<pre class="programlisting"><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gchar"><span class="returnvalue">gchar</span></a> *
gst_pb_utils_get_sink_description (<em class="parameter"><code>const <a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gchar"><span class="type">gchar</span></a> *protocol</code></em>);</pre>
<p>Returns a localised string describing a sink element handling the protocol
specified in <em class="parameter"><code>protocol</code></em>
, for use in error dialogs or other messages to be
seen by the user. Should never return NULL unless <em class="parameter"><code>protocol</code></em>
 is invalid.</p>
<p>This function is mainly for internal use, applications would typically
use <a class="link" href="gst-plugins-base-libs-Missing-plugins.html#gst-missing-plugin-message-get-description" title="gst_missing_plugin_message_get_description ()"><code class="function">gst_missing_plugin_message_get_description()</code></a> to get a description of
a missing feature from a missing-plugin message.</p>
<div class="refsect3">
<a name="gst-pb-utils-get-sink-description.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody><tr>
<td class="parameter_name"><p>protocol</p></td>
<td class="parameter_description"><p>the protocol the sink element needs to handle, e.g. "http"</p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
<div class="refsect3">
<a name="gst-pb-utils-get-sink-description.returns"></a><h4>Returns</h4>
<p> a newly-allocated description string, or NULL on error. Free
string with <a href="/usr/share/gtk-doc/html/glib/glib-Memory-Allocation.html#g-free"><code class="function">g_free()</code></a> when not needed any longer.</p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="gst-pb-utils-get-decoder-description"></a><h3>gst_pb_utils_get_decoder_description ()</h3>
<pre class="programlisting"><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gchar"><span class="returnvalue">gchar</span></a> *
gst_pb_utils_get_decoder_description (<em class="parameter"><code>const <a href="/usr/share/gtk-doc/html/gstreamer-1.0/GstCaps.html#GstCaps-struct"><span class="type">GstCaps</span></a> *caps</code></em>);</pre>
<p>Returns a localised string describing an decoder for the format specified
in <em class="parameter"><code>caps</code></em>
, for use in error dialogs or other messages to be seen by the user.
Should never return NULL unless <em class="parameter"><code>factory_name</code></em>
 or <em class="parameter"><code>caps</code></em>
 are invalid.</p>
<p>This function is mainly for internal use, applications would typically
use <a class="link" href="gst-plugins-base-libs-Missing-plugins.html#gst-missing-plugin-message-get-description" title="gst_missing_plugin_message_get_description ()"><code class="function">gst_missing_plugin_message_get_description()</code></a> to get a description of
a missing feature from a missing-plugin message.</p>
<div class="refsect3">
<a name="gst-pb-utils-get-decoder-description.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody><tr>
<td class="parameter_name"><p>caps</p></td>
<td class="parameter_description"><p>the (fixed) <a href="/usr/share/gtk-doc/html/gstreamer-1.0/GstCaps.html#GstCaps-struct"><span class="type">GstCaps</span></a> for which an decoder description is needed</p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
<div class="refsect3">
<a name="gst-pb-utils-get-decoder-description.returns"></a><h4>Returns</h4>
<p> a newly-allocated description string, or NULL on error. Free
string with <a href="/usr/share/gtk-doc/html/glib/glib-Memory-Allocation.html#g-free"><code class="function">g_free()</code></a> when not needed any longer.</p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="gst-pb-utils-get-encoder-description"></a><h3>gst_pb_utils_get_encoder_description ()</h3>
<pre class="programlisting"><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gchar"><span class="returnvalue">gchar</span></a> *
gst_pb_utils_get_encoder_description (<em class="parameter"><code>const <a href="/usr/share/gtk-doc/html/gstreamer-1.0/GstCaps.html#GstCaps-struct"><span class="type">GstCaps</span></a> *caps</code></em>);</pre>
<p>Returns a localised string describing an encoder for the format specified
in <em class="parameter"><code>caps</code></em>
, for use in error dialogs or other messages to be seen by the user.
Should never return NULL unless <em class="parameter"><code>factory_name</code></em>
 or <em class="parameter"><code>caps</code></em>
 are invalid.</p>
<p>This function is mainly for internal use, applications would typically
use <a class="link" href="gst-plugins-base-libs-Missing-plugins.html#gst-missing-plugin-message-get-description" title="gst_missing_plugin_message_get_description ()"><code class="function">gst_missing_plugin_message_get_description()</code></a> to get a description of
a missing feature from a missing-plugin message.</p>
<div class="refsect3">
<a name="gst-pb-utils-get-encoder-description.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody><tr>
<td class="parameter_name"><p>caps</p></td>
<td class="parameter_description"><p>the (fixed) <a href="/usr/share/gtk-doc/html/gstreamer-1.0/GstCaps.html#GstCaps-struct"><span class="type">GstCaps</span></a> for which an encoder description is needed</p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
<div class="refsect3">
<a name="gst-pb-utils-get-encoder-description.returns"></a><h4>Returns</h4>
<p> a newly-allocated description string, or NULL on error. Free
string with <a href="/usr/share/gtk-doc/html/glib/glib-Memory-Allocation.html#g-free"><code class="function">g_free()</code></a> when not needed any longer.</p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="gst-pb-utils-get-element-description"></a><h3>gst_pb_utils_get_element_description ()</h3>
<pre class="programlisting"><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gchar"><span class="returnvalue">gchar</span></a> *
gst_pb_utils_get_element_description (<em class="parameter"><code>const <a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gchar"><span class="type">gchar</span></a> *factory_name</code></em>);</pre>
<p>Returns a localised string describing the given element, for use in
error dialogs or other messages to be seen by the user. Should never
return NULL unless <em class="parameter"><code>factory_name</code></em>
 is invalid.</p>
<p>This function is mainly for internal use, applications would typically
use <a class="link" href="gst-plugins-base-libs-Missing-plugins.html#gst-missing-plugin-message-get-description" title="gst_missing_plugin_message_get_description ()"><code class="function">gst_missing_plugin_message_get_description()</code></a> to get a description of
a missing feature from a missing-plugin message.</p>
<div class="refsect3">
<a name="gst-pb-utils-get-element-description.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody><tr>
<td class="parameter_name"><p>factory_name</p></td>
<td class="parameter_description"><p>the name of the element, e.g. "giosrc"</p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
<div class="refsect3">
<a name="gst-pb-utils-get-element-description.returns"></a><h4>Returns</h4>
<p> a newly-allocated description string, or NULL on error. Free
string with <a href="/usr/share/gtk-doc/html/glib/glib-Memory-Allocation.html#g-free"><code class="function">g_free()</code></a> when not needed any longer.</p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="gst-pb-utils-add-codec-description-to-tag-list"></a><h3>gst_pb_utils_add_codec_description_to_tag_list ()</h3>
<pre class="programlisting"><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a>
gst_pb_utils_add_codec_description_to_tag_list
                               (<em class="parameter"><code><a href="/usr/share/gtk-doc/html/gstreamer-1.0/GstTagList.html#GstTagList-struct"><span class="type">GstTagList</span></a> *taglist</code></em>,
                                <em class="parameter"><code>const <a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gchar"><span class="type">gchar</span></a> *codec_tag</code></em>,
                                <em class="parameter"><code>const <a href="/usr/share/gtk-doc/html/gstreamer-1.0/GstCaps.html#GstCaps-struct"><span class="type">GstCaps</span></a> *caps</code></em>);</pre>
<p>Adds a codec tag describing the format specified by <em class="parameter"><code>caps</code></em>
 to <em class="parameter"><code>taglist</code></em>
.</p>
<div class="refsect3">
<a name="gst-pb-utils-add-codec-description-to-tag-list.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>taglist</p></td>
<td class="parameter_description"><p>a <a href="/usr/share/gtk-doc/html/gstreamer-1.0/GstTagList.html#GstTagList-struct"><span class="type">GstTagList</span></a></p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>codec_tag</p></td>
<td class="parameter_description"><p>a GStreamer codec tag such as <a href="/usr/share/gtk-doc/html/gstreamer-1.0/GstTagList.html#GST-TAG-AUDIO-CODEC:CAPS"><span class="type">GST_TAG_AUDIO_CODEC</span></a>,
<a href="/usr/share/gtk-doc/html/gstreamer-1.0/GstTagList.html#GST-TAG-VIDEO-CODEC:CAPS"><span class="type">GST_TAG_VIDEO_CODEC</span></a> or <a href="/usr/share/gtk-doc/html/gstreamer-1.0/GstTagList.html#GST-TAG-CODEC:CAPS"><span class="type">GST_TAG_CODEC</span></a>. If none is specified,
the function will attempt to detect the appropriate category. </p></td>
<td class="parameter_annotations"><span class="annotation">[<acronym title="NULL is OK, both for passing and for returning."><span class="acronym">allow-none</span></acronym>]</span></td>
</tr>
<tr>
<td class="parameter_name"><p>caps</p></td>
<td class="parameter_description"><p>the (fixed) <a href="/usr/share/gtk-doc/html/gstreamer-1.0/GstCaps.html#GstCaps-struct"><span class="type">GstCaps</span></a> for which a codec tag should be added.</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect3">
<a name="gst-pb-utils-add-codec-description-to-tag-list.returns"></a><h4>Returns</h4>
<p> TRUE if a codec tag was added, FALSE otherwise.</p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="gst-pb-utils-get-codec-description"></a><h3>gst_pb_utils_get_codec_description ()</h3>
<pre class="programlisting"><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gchar"><span class="returnvalue">gchar</span></a> *
gst_pb_utils_get_codec_description (<em class="parameter"><code>const <a href="/usr/share/gtk-doc/html/gstreamer-1.0/GstCaps.html#GstCaps-struct"><span class="type">GstCaps</span></a> *caps</code></em>);</pre>
<p>Returns a localised (as far as this is possible) string describing the
media format specified in <em class="parameter"><code>caps</code></em>
, for use in error dialogs or other messages
to be seen by the user. Should never return NULL unless <em class="parameter"><code>caps</code></em>
 is invalid.</p>
<p>Also see the convenience function
<a class="link" href="gst-plugins-base-libs-Descriptions.html#gst-pb-utils-add-codec-description-to-tag-list" title="gst_pb_utils_add_codec_description_to_tag_list ()"><code class="function">gst_pb_utils_add_codec_description_to_tag_list()</code></a>.</p>
<div class="refsect3">
<a name="gst-pb-utils-get-codec-description.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody><tr>
<td class="parameter_name"><p>caps</p></td>
<td class="parameter_description"><p>the (fixed) <a href="/usr/share/gtk-doc/html/gstreamer-1.0/GstCaps.html#GstCaps-struct"><span class="type">GstCaps</span></a> for which an format description is needed</p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
<div class="refsect3">
<a name="gst-pb-utils-get-codec-description.returns"></a><h4>Returns</h4>
<p> a newly-allocated description string, or NULL on error. Free
string with <a href="/usr/share/gtk-doc/html/glib/glib-Memory-Allocation.html#g-free"><code class="function">g_free()</code></a> when not needed any longer.</p>
</div>
</div>
</div>
<div class="refsect1">
<a name="gst-plugins-base-libs-Descriptions.other_details"></a><h2>Types and Values</h2>
</div>
</div>
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